I have a squeaky sound that comes from the plastic center sunroof support. While driving if you hear a squeak reach back and press up on the plastic support. You can also try closing the shade. If it goes away you've got the same issue.
2006 X5 with 45000 miles. First started @ 25k and have taken it in 3 times since. Now it's backkkkk.
Calling the Service Manager Monday.